c-- ccc ccd cce cco ccv cdc cdd cde cdo cdv ce- cec ced cee ceo cev co- coc cod coe coo cov cvc cvd cve cvo cvv dcc dcd dce dco dcv ddc ddd dde ddo de- dec ded dee deo dev doc dod doe doo dov dvc dvd dve ec- ecc ecd ece eco ecv ed- edc edd ede edo eec eed eee eeo eev eo- eoc eod eoe eoo evc evd eve evo evv oc- occ ocd oco ocv odc odd ode odo odv oec oed oee oeo oo- ooc ood ooo oov ov- ovc ovd ove ovo ovv v-e vcc vcd vce vco vdc vdd vde vdo vdv vec ved vee veo voc vod voe voo vov vvc vvo vvv